# Set & Map in Javascript

 let set = new Set();  // initializes a new set

### properties on set

  1. set.add(value)
  2. set.clear() // removes all
  3. set.delete(val) // deletes val and returns boolean
  4. set.has(val) // check if exists and return boolean
  5. set.size() // gives size

### iterate over set with for..of

 for(let item of set) console.log(item);

### set to array and vice-versa

 let set  = new Set([1,2,3,4,4]);
 let arr = [...set];

 let map = new Map();  // initializes a new map

### properties on map

  1. set.set(key,value)
  2. set.clear() // removes all
  3. set.delete(key) // deletes key val and returns boolean
  4. set.has(key) // check if exists and return boolean
  5. set.size() // gives size

### iterate over map with for..of

 1. for(let key of map.keys()) console.log(key);
 
 2.for(let [key, value] of map) console.log(key,'=',value);

### array to map conversion

 let map  = new map([['key1','val1'],['key2','val2'],['key3','val3']]);